Novel carbazole-based multifunctional materials with a hybridized local and charge-transfer excited state acting as deep-blue emitters and phosphorescent hosts for highly efficient organic light-emitting diodes

Abstract

In this work, two carbazole- and benzo[d]oxazole-based novel multifunctional materials with hybridized local and charge-transfer (HLCT) characteristic, namely OCI and OCT, which could act as deep-blue fluorophors and phosphorescent hosts,...

Combining intrinsic (blue) and exciplex (green and orange-red) emissions of the same material (OCT) in white organic light-emitting diodes to realize high color quality with a CRI of 97

“…4(a). 36 Clearly, the intrinsic and formed exciplex emissions for OCT cover almost all the visible light region, from the deep blue to the deep red light wavebands, and the triangle formed by connecting the three points of the CIE coordinates for the above OCT-based blue, green and orange-red devices perfectly encloses the white light region in the 1931' CIE coordinates diagram, as displayed in Fig. 4(b).…”

“…Its high electron mobility and suitable LUMO level of -2.18 eV indicate that OCT has great potential for use as an outstanding electron acceptor material. 36 In this work, employing OCT as an electron acceptor and matching with different electron donors (1,1 0 -bis[4-(di-p-tolylamino) phenyl]cyclohexane (TAPC) and 4,4 0 ,4 00 -tris(N-3-methylphenyl-N-phenyl-am-ino)triphenylamine (m-MTDATA)), green and orange-red exciplex-based OLEDs were firstly demonstrated; they demonstrate emission peaks located at 524 nm and 596 nm and broader full widths at half maximum, reaching 102 nm and 117 nm, respectively, which are quite beneficial for developing high-color-quality white OLEDs. Moreover, the green device realizes high EL performance, with the maximum current efficiency (CE), power efficiency (PE) and EQE reaching 34.6 cd A À1 , 40.2 lm W À1 , and 10.6%, respectively; this originates from efficient RISC due to a small DE ST for the TAPC:OCTforming exciplex.…”

“…Its high electron mobility and suitable LUMO level of -2.18 eV indicate that OCT has great potential for use as an outstanding electron acceptor material. 36…”

Deep Blue Emitter Based on Tris(triazolo)triazine Moiety with CIEy < 0.08 for Highly Efficient Solution‐Processed Organic Light‐Emitting Diodes Via Molecular Strategy of “Hot Excitons”

“…With this in mind, many HLCT‐based deep/pure blue materials have been developed recently. [ 29–42 ] However, most of these emitters were utilized in OLED via vacuum deposition method. Very few exploration has been performed on the solution processable OLED based on deep/pure blue HLCT emitters.…”

A universal bipolar host based on isonicotinonitrile and carbazole for efficient red, green and blue PhOLEDs

“…In addition, the efficiency roll-off of device G1 is relatively small as the EQE remains to be 20.00 and 19.24% at the brightness of 100 and 1000 cd m À2 with only 0.2% and 4.0% decrease. The EL performance is significantly better than those reported for CBP-based green devices, 33,[35][36][37] indicating that BCz3PhCN could be an excellent host for green PhOLEDs.…”